$ { \left[\begin{array}{rr}{2} & {-1} \\ {-1} & {0}\end{array}\right]-\left[\begin{array}{rr}{0} & {3} \\ {2} & {0}\end{array}\right] = {?} } $
Answer: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{2}-{0} & {-1}-{3} \\ {-1}-{2} & {0}-{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{2} & {-4} \\ {-3} & {0}\end{array}\right]}$